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Oct 2, 2020
10/20

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Colloque d'analyse harmonique non commutative (3rd : 1978 : Université d'Aix-Marseille Luminy)

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244 pages ; 25 cm

Topics: Harmonic analysis -- Congresses, Lie algebras -- Congresses, Lie groups -- Congresses, Analyse...

An algorithm was developed which can be used to obtain the equations. In a more general context, the algorithm computes a real nonsingular similarity transformation matrix which reduces a real nonsymmetric matrix to block diagonal form, each block of which is a real quasi upper triangular matrix. The algorithm works with both defective and derogatory matrices and when and if it fails, the resultant output can be used as a guide for the reformulation of the mathematical equations that lead up to...

Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, FEEDBACK CONTROL, FREQUENCY ANALYZERS, NUMERICAL...

The Wing and Rotor Aeroelastic Test System (WRATS) data acquisition system (DAS) is a 64-channel data acquisition display and analysis system specifically designed for use with the WRATS 1/5-scale V-22 tiltrotor model of the Bell Osprey. It is the primary data acquisition system for experimental aeroelastic testing of the WRATS model for the purpose of characterizing the aeromechanical and aeroelastic stability of prototype tiltrotor configurations. The WRATS DAS was also used during...

Topics: NASA Technical Reports Server (NTRS), DATA ACQUISITION, ROTARY WING AIRCRAFT, AEROELASTICITY, V-22...

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x, 449 pages ; 25 cm

Topics: Harmonic analysis -- Congresses, Analyse harmonique -- Congrès, Harmonic analysis, Harmonische...

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viii, 287 p. ; 25 cm

Topic: Harmonic analysis -- Congresses

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187 p. ; 24 cm

Topics: Harmonic analysis -- Congresses, Lie groups -- Congresses

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Jun 24, 2020
06/20

by
Colloque d'analyse harmonique non commutative (1st : 1974 : Université d'Aix-Marseille Luminy)

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vi, 231 pages ; 25 cm

Topics: Harmonic analysis -- Congresses, Lie algebras -- Congresses, Locally compact groups -- Congresses,...

Acoustic measurements were made on the exterior and interior of a general aviation turboprop airplane during four flight tests. The test conditions were carefully controlled and repeated for each flight in order to determine data variability. For the first three flights the cabin was untreated and for the fourth flight the fuselage was treated with glass fiber batts. On the exterior, measured propeller harmonic sound pressure levels showed typical standard deviations of +1.4 dB, -2.3 dB, and...

Topics: NASA Technical Reports Server (NTRS), ACOUSTIC MEASUREMENT, AIRCRAFT COMPARTMENTS, FLIGHT TESTS,...

This is a preliminary study of possible necessary and sufficient conditions to insure stationarity in the solution process for a stochastic differential equation. It indirectly sheds some light on ergodicity properties and shows that the spectral density is generally inadequate as a statistical measure of the solution. Further work is proceeding on a more general theory which gives necessary and sufficient conditions in a form useful for applications.

Topics: NASA Technical Reports Server (NTRS), DIFFERENTIAL EQUATIONS, PROBLEM SOLVING, STOCHASTIC...

Methods for solving problems encountered in separating the core field from the crustal field are summarized as well as those methods developed for inverting total magnetic field data to obtain source functions for oceanic areas. Accounting for magnetization contrasts and the magnetization values measured in rocks of marine origin are also discussed.

Topics: NASA Technical Reports Server (NTRS), EARTH CORE, EARTH CRUST, GEOMAGNETISM, MAGNETIC ANOMALIES,...

The structure-borne contribution to the interior noise that is induced by the propeller wake acting on the wing was studied. Analytical models were developed to describe each aspect of this path including the excitation loads, the wing and fuselage structures, and the interior acoustic space. The emphasis is on examining a variety of parameters, and as a result different models were developed to examine specific parameters. The excitation loading on the wing by the propeller wake is modeled by...

Topics: NASA Technical Reports Server (NTRS), AIRCRAFT COMPARTMENTS, AIRCRAFT NOISE, HARMONIC ANALYSIS,...

An apparatus suitable for turbulence measurement between ranges of 1 to 5000 cps and from 6 to 16,000 cps was developed and is described. Turbulence spectra downstream of the grills were examined with reference to their general characteristics, their LF qualities, and the effects of periodic turbulence. Medium and HF are discussed. Turbulence spectra in the boundary layers are similarly examined, with reference to their fluctuations at right angles to the wall, and to lateral fluctuations....

Topics: NASA Technical Reports Server (NTRS), HARMONIC ANALYSIS, SPECTRAL ENERGY DISTRIBUTION, SPECTRUM...

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Oct 21, 2020
10/20

by
Zygmund, Antoni, 1900-

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iv, 52, [1] p. 26 cm

Topics: Harmonic analysis, Integrals

The computation of firing tables for guided missiles is a problem that first arose when the U.S. Army introduced the Redstone Missile into its arsenal of weapons. The repetitive nature of such computations, their continuing requirement, and the turnover in personnel create a need for systemization of computations, applicable for different missile systems and at the same time, not requiring extensive analysis, new computer programs, and training of personnel. Recent work done by the Computing...

Topics: DTIC Archive, Breaux, Harold J, ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD, *RANGE...

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Jul 22, 2020
07/20

by
Reiter, Hans, 1921-

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xi, 126 p. ; 25 cm

Topics: Harmonic analysis, Locally compact Abelian groups, Segal algebras

Despite the importance of sea breeze, only Hendrickson and MacMahanâ s research has been done to determine sea breeze effects in Monterey Bay; other than that not much research has been done. In this thesis, CODAR SeaSonde radars are used to map the surface current in Monterey Bay. Temperature, wind speed and wind direction are analyzed for five locations to establish the algorithm for determining the sea breeze days in Monterey Bay. Harmonic analysis is used to understand the relationship...

Topics: Sea Breeze, Coastal jet, HF Radar derived surface currents, Harmonic analysis

The data sets used in geomagnetic field modeling at GSFC are described. Data are measured and obtained from a variety of information and sources. For clarity, data sets from different sources are categorized and processed separately. The data base is composed of magnetic observatory data, surface data, high quality aeromagnetic, high quality total intensity marine data, satellite data, and repeat data. These individual data categories are described in detail in a series of notebooks in the...

Topics: NASA Technical Reports Server (NTRS), AEROMAGNETISM, DATA BASES, GEOMAGNETISM, MATHEMATICAL MODELS,...

A harmonic power flow program applicable to space power systems with sources of harmonic distortion is described. The algorithm is a modification of the Electric Power Research Institute's HARMFLO program which assumes a three phase, balanced, AC system with loads of harmonic distortion. The modified power flow program can be used with single phase, AC systems. Early results indicate that the required modifications and the models developed are quite adequate for the analysis of a 20 kHz testbed...

Topics: NASA Technical Reports Server (NTRS), AC GENERATORS, APPLICATIONS PROGRAMS (COMPUTERS),...

High-frequency radar (HFR) data were used to describe the general surface circulation patterns, including the mesoscale upwelling events of the coastal region located southwest of Lisbon, Portugal. This dynamically complex region has been studied before using scarce measurements of limited duration. The results shown here reveal the capabilities of this measurement system and provide an immense contribution to this field of study, which is now able to profit from longer datasets with both high...

Topics: high-frequency radar, HFR, surface currents, surface current patterns, oceanography, coastal...

A Fortran program has been written for the purpose of carrying out a generalized harmonic analysis of a digitized time function. This analysis procedure, as well as the program itself, will be described in this memorandum.

Topics: DTIC Archive, Hassell,Beverly C, NAVY UNDERWATER SOUND LAB NEW LONDON CONN, *POWER SPECTRA,...

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iv, 325 pages : 25 cm

Topics: Harmonic analysis -- Congresses, Analyse harmonique -- Congrès, Harmonic analysis, Harmonische...

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Oct 26, 2020
10/20

by
Brezin, Jonathan, 1943-

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v, 177 p. ; 25 cm

Topics: Harmonic analysis, Homogeneous spaces

The normal mode solution of the problem of the radiation field of a simple harmonic source in a layered waveguide is extended to the case of small irregularities in the surface. The theory is used to calculate the radiation field of a 147.8 cps simple harmonic source in about 20 m of shallow water over a thick layer of unconsolidated sediment. The calculations indicate that the effects of small surface roughness, i.e., rms wave height about half m. are to increase the attenuation as a function...

Topics: DTIC Archive, Clay,C S, COLUMBIA UNIV DOBBS FERRY NY HUDSON LABS, *ACOUSTIC WAVES, *THEORY,...

Topics: DTIC Archive, MASSACHUSETTS INST OF TECH CAMBRIDGE, *CRYSTAL STRUCTURE, *SOLID STATE PHYSICS,...

A survey is made of the mathematical properties of, and the arithmetic relationships between various distributions on the circle and the sphere. Some new results are given. The Brownian motion and Angular Gaussian distributions are shown in computer drawn graphs to bracket the von Mises-Fisher distributions. (Author)

Topics: DTIC Archive, Watson,Geoffrey S, PRINCETON UNIV NJ DEPT OF STATISTICS, *PROBABILITY DISTRIBUTION...

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ix, 226 p. ; 25 cm

Topic: Harmonic analysis -- Congresses

Over the last decade, the utility of geomagnetic field models or the mathematical representations of the geomagnetic field has expanded considerably, both for civilian and military applications. Such an increase has been accompanied with more interest in models and demands for better accuracies with resultant changes in techniques of model computations and input data requirements. Additionally, such a detailed overview of geomagnetic field models provides a vantage point for reviewing the role...

Topics: DTIC Archive, Regan, Robert D, PHOENIX CORP FALLS CHURCH VA, *GEOMAGNETISM, *MAGNETIC FIELDS,...

Over the last decade, the utility of geomagnetic field models or the mathematical representations of the geomagnetic field has expanded considerably, both for civilian and military applications. Such an increase has been accompanied with more interest in models and demands for better accuracies with resultant changes in techniques of model computations and input data requirements. Additionally, such a detailed overview of geomagnetic field models provides a vantage point for reviewing the role...

Topics: DTIC Archive, Regan, Robert D, PHOENIX CORP FALLS CHURCH VA, *GEOMAGNETISM, *MAGNETIC FIELDS,...

An accurate and efficient method of computing unsteady transonic flow is described. The flow is linearized about an experimentally measured or numerically calculated steady state, as represented by a given pressure distribution. For a given mode of motion, the amplitudes and phase lags of the lift and moment coefficients at a given reduced frequency are found by superposition from an indicial response. The computational effort is reduced by treating shock waves as discontinuities, and by...

Topics: DTIC Archive, Seebass,A Richard, ARIZONA UNIV TUCSON ENGINEERING EXPERIMENT STATION, *Transonic...

The orbit of Cosmos 837 rocket (1976-62E) has been determined at 36 epochs between January and September 1978, using the RAE orbit refinement program PROP6 with about 3000 observations. The inclination was 62.7 degrees and the eccentricity 0.039. The orbital accuracy achieved was between 30 m and 150 m, both radial and crosstrack. The orbit was near 29:2 resonance in 1978 (exact resonance occurred on May 14) and the values of orbital inclination obtained have been analyzed to derived lumped...

Topics: DTIC Archive, Hiller,H, ROYAL AIRCRAFT ESTABLISHMENT FARNBOROUGH (ENGLAND), *EARTH ORBITS,...

This report presents some numerical methods for estimating spherical harmonic coefficients from data sampled on the sphere. The data may be given in the form of area means or of point values, and it may be free from errors or affected by measurement 'noise'. The case discussed to greatest length is that of complete, global data sets on regular grids (i.e., lines of latitude and longitude, the latter, at least, separated by constant interval); the case where data are sparsely and irregularly...

Topics: DTIC Archive, Colombo, Oscar L, OHIO STATE UNIV COLUMBUS DEPT OF GEODETIC SCIENCE AND SURVEYING,...

This report presents some numerical methods for estimating spherical harmonic coefficients from data sampled on the sphere. The data may be given in the form of area means or of point values, and it may be free from errors or affected by measurement 'noise'. The case discussed to greatest length is that of complete, global data sets on regular grids (i.e., lines of latitude and longitude, the latter, at least, separated by constant interval); the case where data are sparsely and irregularly...

Topics: DTIC Archive, Colombo, Oscar L, OHIO STATE UNIV COLUMBUS DEPT OF GEODETIC SCIENCE AND SURVEYING,...

This report presents some numerical methods for estimating spherical harmonic coefficients from data sampled on the sphere. The data may be given in the form of area means or of point values, and it may be free from errors or affected by measurement 'noise'. The case discussed to greatest length is that of complete, global data sets on regular grids (i.e., lines of latitude and longitude, the latter, at least, separated by constant interval); the case where data are sparsely and irregularly...

Topics: DTIC Archive, Colombo, Oscar L, OHIO STATE UNIV COLUMBUS DEPT OF GEODETIC SCIENCE AND SURVEYING,...

Possible preferred-frame effects on stellar stability were examined and no new instabilities were found. In particular, it is shown that: (1) Although terms linear in the preferred-frame velocity w (time-odd terms, analogous to viscosity and energy generation) change the shapes of the normal modes, their symmetry properties prevent them from changing the characteristic frequencies. Thus, no new vibrational or secular instabilities can occur. (2) Terms quadratic in w do not change either the...

Topics: NASA Technical Reports Server (NTRS), GRAVITATION THEORY, STELLAR GRAVITATION, HARMONIC ANALYSIS,...

The primary goal of the current gravity gradiometer research at Stanford has been to establish the feasibility of using a gravity gradiometer with 1 E accuracy, as the primary sensor in various applications. The two applications considered here in detail are geodesy missions and inertial navigation systems. Preliminary sections on gravity models and gravity gradiometer bias estimation are also included.

Topics: NASA Technical Reports Server (NTRS), GEODESY, INERTIAL NAVIGATION, MAGNETOMETERS, ERROR ANALYSIS,...

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xv, 319 p. : 21 cm

Topic: Harmonic analysis -- Congresses

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4.0

Oct 8, 2020
10/20

by
Auslander, Louis

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98 pages ; 25 cm

Topics: Lie groups, Manifolds (Mathematics), Harmonic analysis, Functions, Theta, Lie, Groupes de,...

Static and dynamic testing of the NASA 0.7 percent scale Hybrid Wing Body (HWB) configuration was conducted in the Rolling Hills Research Corporation water tunnel to investigate aerodynamic behavior over a large range of angle-of-attack and to develop models that can predict aircraft response in nonlinear unsteady flight regimes. This paper reports primarily on the longitudinal axis results. Flow visualization tests were also performed. These tests provide additional static data and new dynamic...

Topics: NASA Technical Reports Server (NTRS), BODY-WING CONFIGURATIONS, AIRCRAFT MODELS, SCALE MODELS,...

The results from a wind tunnel test of a small scale free-tip rotor are analyzed. The free-tip rotor has blade tips that are free to weathervane into the tip's relative wind, thus producing a more uniform lift around the azimuth. The free-tip assembly, which includes the controller, functioned flawlessly throughout the test. In a test of the free-tip's response after passing through a vertical air jet, the tip pitched freely and in a controlled manner. Analysis of the tip's response...

Topics: NASA Technical Reports Server (NTRS), BLADE TIPS, HELICOPTER DESIGN, PROPULSIVE EFFICIENCY, ROTARY...

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iv, 169 pages 26 cm

Topics: Harmonic analysis -- Congresses, Functions of several complex variables -- Congresses, Analyse...

Arrival directions of air showers with primary energies in the range 10 to the 16.5 power eV to 10 to the 18th power eV show the first harmonic in right ascension (RA) with amplitude of 2.7 + or - 1.0% and phase of 13-16h. However, the second harmonic in RA slightly seen for showers in the range 10 to the 18th power eV to 10 to the 19th power eV disappeared by accumulation of observed showers. The distribution of arrival directions of low-mu air showers with primary energies around 10 to the...

Topics: NASA Technical Reports Server (NTRS), ANISOTROPY, COSMIC RAY SHOWERS, ENERGY SPECTRA, GAMMA RAYS,...

Experimental studies of isolated rotors in forward flight have indicated that higher harmonic pitch control can reduce rotor noise. These tests also show that such pitch inputs can generate substantial vibratory loads. The modification is summarized of the RotorCRAFT (Computation of Rotor Aerodynamics in Forward flighT) analysis of isolated rotors to study the vibratory loading generated by high frequency pitch inputs. The original RotorCRAFT code was developed for use in the computation of...

Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC NOISE, HARMONIC CONTROL, NEAR WAKES, NOISE...

Conventional gravity and magnetic anomaly continuation invokes the standard Poisson boundary condition of a zero anomaly at an infinite vertical distance from the observation surface. This simple continuation is limited, however, where multiple altitude slices of the anomaly field have been observed. Increasingly, areas are becoming available constrained by multiple boundary conditions from surface, airborne, and satellite surveys. This paper describes the implementation of continuation with...

Topics: NASA Technical Reports Server (NTRS), BOUNDARY CONDITIONS, POINT SOURCES, SPHERICAL CAPS, HARMONIC...

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Oct 5, 2020
10/20

by
Nillsen, Rodney Victor, 1945-

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xii, 186 pages ; 24 cm

Topics: Harmonic analysis, Fourier transformations, Singular integrals, Analyse harmonique, Fourier,...

The size of the variance-covariance matrix of the data, used to obtain minimum variance estimators for collocation, is as large as the number of observations in the data set. For some arrangements of the data, such as the usual 'equal angle' (or 'regular') grid, the matrix presents a very strong Toeplitz-circulant structure that can be exploited to reduce computing in setting-up and inverting the matrix. This reduction can be quite drastic. This report discusses such structure and presents an...

Topics: DTIC Archive, Colombo,Oscar L, OHIO STATE UNIV COLUMBUS DEPT OF GEODETIC SCIENCE, *ANALYSIS OF...

The satellite 1971-54A entered a near-circular orbit with period 95.9 minutes and inclination 90.2 deg. Between 1972 and 1978 the orbit passed slowly through 15th-order resonance, when the track over the Earth repeats after 15 revolutions, and the 15th- and 30th-order harmonics in the geopotential may produce substantial orbital perturbations. The values of orbital inclination and eccentricity from 269 weekly US Navy orbits between November 1972 and January 1978 have been analysed to determine...

Topics: DTIC Archive, King-Hele,D G, ROYAL AIRCRAFT ESTABLISHMENT FARNBOROUGH (ENGLAND), *EARTH ORBITS,...

Topics: DTIC Archive, Harris, P. M., OHIO STATE UNIV RESEARCH FOUNDATION COLUMBUS MCPHERSON CHEMICAL LAB,...

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viii, 225 pages ; 25 cm

Topics: Martingales (Mathematics) -- Congresses, Harmonic analysis -- Congresses, Banach spaces --...

System uses phase-locked loops to give real-time information on speech spectrum by tracking the fundamental and its first 19 harmonics.

Topics: NASA Technical Reports Server (NTRS), HARMONIC ANALYSIS, HARMONICS, PHASE LOCKED SYSTEMS, SPEECH,...

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Jun 27, 2010
06/10

by
Hodder, D. T.; Kimball, R. B.; Wrinkle, W. W., Jr

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Barium-copper oxide/canister barium vapor release system for geomagnetospheric measurements

Topics: BANACH SPACE, DIFFERENTIAL EQUATIONS, FIXED POINTS (MATHEMATICS), LIAPUNOV FUNCTIONS, PERIODIC...